It has been recently determined that endogenous interferon plays not only central role to bio-defensive mechanism against virus infections and microbial infections, but also an important role dn antitumor and immune modulator. Mass production of interferon is established. Namely, it is possible to obtain of natural interferon by cell culture and also to produce a large amount of recombinant interferon from E. coli transferred with a gene of interferon and therefore, many research achievements on these interferons have accumulated. For example, many kinds of biological activity on interferon, such as antiviral activity, prevention of cell growth and immune modulation have been confirmed and interferon is practiced on clinics as treating agents for virus infected diseases, such as hepatitis C and hepatitis B, anticancer agents and therapeutic agents for immunologic disease. Furthermore, it is suggested that interferon will prevent carcinogenesis by hepatitis C and hepatitis B.
Since there is no therapeutic method for almost of the above diseases, interferon is especially made much of.